Calling it a story campaign is generous; it's literally just the end of the game again. You get to see all the same cutscenes again, with certain scenes extended, but it also definitely isnt just the end of the game because at the end you fight a different final boss and it also doesnt retell the final boss fight despite forcing you to replay literally every encounter prior.
This would have been so much better as actual extra scenes applied to the base game; it's like a weird, jarring clip show. Or viewing deleted scenes in the dvd extras. What it definitely isnt is an improvement.
It's amazing how the format itself assassinated the storytelling; this needed to be a final mix, rather than a seperate, disjointed experience. I paid thirty bucks for this, but christ i wish i just paid sixty for final mix and could resell my old copy. And new customers would be able to pay $60 for a fixed game rather than $90 for a story that is still told in such an awkward fashion.
The bulk of the new story seems to be located after the limit cut (boss rush) anyway, and thats where all the good fights are, so...what is the point of Remind? Why do it this way? Why not just fix the ending for free, for everyone, and charge me $30 for limit cut? The game is not better for this. The gameplay fixes and limit cut are the only things of worth.

Tl;dr Remind is three hours but theres maybe half an hour of new shit, a couple great new setpieces and fights. The rest is exactly the same as the end of KH3.
I am like,

red alert klaxons blaring

asking you all not to buy this until it's at least half off. The boss fights are awesome but that's basically all you get.